In general, a bipolar junction transistor (a bipolar transistor, BJT) may be manufactured in semiconductor technology via commonly applied semiconductor processing including for example layering, patterning, doping, thermal annealing, and the like. A bipolar transistor usually includes a collector, a base, and an emitter, wherein an applied voltage between the emitter and the base may be used to control a current flow between the emitter and the collector. Bipolar transistors are conventionally classified into the npn-type and the pnp-type with an emitter-base junction and a base-collector junction, respectively. Further, a bipolar junction transistor may be configured as a heterojunction bipolar transistor (HBT), wherein the emitter-base junction and the base-collector junction include different semiconductor materials creating a so-called heterojunction. Moreover, an HBT may be manufactured in SiGe technology, as a SiGe-HBT, wherein the base of a SiGe-HBT may include a silicon/germanium alloy, e.g. the base of the SiGe-HBT may be graded to provide the emitter-base junction differing from the base-collector junction.